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Mathematics 220 Homework for Week 3 Due: September 26, Friday Problems from Chapters 2 of the 3rd edition of the text. • 2.18, 2.20, 2.32, 2.48, 2.54, 2.60, 2.64, 2.68, 2.72 If you are using the 2nd edition, be careful — question numbers may not agree. • Determine whether the following four statements are true or false, and justify your answers (“true” or “false” is not sufficient). (i) 8x 2 R, 8y 2 R, xy = x + y. (ii) 8x 2 R, 9y 2 R s.t. xy = x + y. (iii) 9x 2 R s.t. 8y 2 R, xy = x + y. (iv) 9x 2 R s.t. 9y 2 R s.t. xy = x + y.